I;J(^L(M;^ oi' .vciih i i;ri i; al riKUXc'rinN in) 



tlu'- past \\ illi i'.\:liausl('(l and ii])ainl(tii('(l .•-loils, (lie |>imi|)1«* <ni 

 these ric'li lands are ai^aiii talkini; of llic " iii('xlianstil)lc fer- 

 tility'' of tlic soil, and huiniiiL;- llicir straw and niainiif «.i' 

 hanlino- tlie latter unto tlic ice to Ix-fonl their slieains. .\ 

 ('(►niparison of Nir^in soil in the ( anadian Nortiiwcsl with soil 

 adioinino- it which had hccii cultivatiMl twenty-two vt-iirs 

 sIiowlmI a loss of nitroo(Mi per acre from (ilKji; to 47-')»'> juinnds, 

 or 2*2(10 pounds, a loss of S-j-50.(MJ wortii (•! introj^cn per acre. 



KKKiii-irv CoNiAiM I) IN Di III: i: I N I ]"\i:M ( i:<>i's 

 (.Xpproximalc! uiaxiniiiin unioiints n'movahli- jn-r :nrt' HuimuUy; 



' Much of thi.s nitrogen is taken from the air, and the root.s go so deep that 

 even the phosphorus and potassium may be largely .supplif<l from layei-s of 

 soil below the reach of other crops. 



